In the United States, the so-called Jim Crow laws (or Black Codes) were made to enforce racial segregation, and included laws that would prevent African-Americans from doing things that a "white" person could do. For instance, Jim Crow laws regulated separate use of water fountains and separate seating sections on public transport. Jim Crow laws varied between communities and states.

As attitudes turned against segregation in the Federal courts after World War II, the segegationist white governments of many of the states of the South East countered with even more numerous and strict segregation laws on the local level until the start of the 1960s.

The modern civil rights movement is often considered to have been sparked by an act of civil disobedience against the Jim Crow laws when Rosa Parks, an African-American woman, refused to give up her seat on a bus to a white man. This led to a series of legislation and court decisions in which Jim Crow laws were repealed or annulled.

The term Jim Crow comes from the minstrel show song "Jump Jim Crow" written in 1828 by Thomas D. Rice, a white man, the originator of blackface performance. The song and blackface itself were an immediate hit and by 1837, Jim Crow was being used to refer to racial segregation.

In conjunction with the laws there was also Jim Crow etiquette: a set of unwritten rules governing how Blacks and Whites should interact. Breaking of this code could result in a lynching (1878-1898 saw 10,000 lynchings) or even a sadistic murder (Sam Hose[?] for example).